EFFECT OF AEROBIC EXERCISE TRAINING WITH AND WITHOUT BLOOD FLOW RESTRICTION ON AEROBIC CAPACITY IN HEALTHY YOUNG ADULTS: A SYSTEMATIC REVIEW WITH META-ANALYSIS.

BACKGROUND: Exercise training (ET) with blood flow restriction (BFR) is becoming increasingly popular, but the majority of BFR ET studies have evaluated skeletal muscle strength and hypertrophy. The favorable effect of BFR ET on skeletal muscle and the vasculature appears to improve aerobic capacity (AC) although conflicting results have been observed.Purpose: The purposes of this systematic review with meta- analysis were to examine the effects of aerobic ET with and without BFR on AC and to compare the effect of low-to-moderate aerobic ET with and without BFR to high-intensity aerobic ET with and without BFR on AC. STUDY DESIGN: Systematic Review with Meta-analysis. METHODS: A comprehensive search for studies examining the effects of aerobic ET with and without BFR on AC was performed. Inclusion criteria were: (a) the study was conducted in healthy individuals, (b) there was random allocation of study participants to training and control groups, (c) BFR was the sole intervention difference between the groups. RESULTS: A total of seven studies (5 low-to-moderate ET and 2 high-intensity ET) were included in the meta-analysis providing data from 121 subjects. There was a significant standardized mean difference (SMD) of 0.38 (95% CI = 0.01, 0.75) in AC between the BFR and non-BFR groups of all seven studies (z = 2.01; p = 0.04). Separate analyses of the five low-to-moderate aerobic ET studies found similar results with aerobic ET with BFR eliciting a significantly greater AC (z = 2.47; p=0.01) than aerobic ET without BFR (SMD of 0.57; 95% CI = 0.12, 1.01). Separate analyses of the two high-intensity aerobic ET studies with and without BFR found no significant difference in AC between the groups (SMD of - 0.01; 95% CI = - 0.67, 0.64). CONCLUSION: Aerobic ET with BFR elicits a significantly greater AC than aerobic ET without BFR in healthy young adults. However, low-to-moderate intensity aerobic ET with BFR elicited a greater improvement in AC than aerobic ET without BFR while high-intensity aerobic ET with BFR did not elicit an improvement in AC over high-intensity aerobic ET without BFR. LEVEL OF EVIDENCE: 1a.